Novel pi-conjugating polymers based on dibenzothiophene were synthesized with a novel dibenzothiophene derivative, 2,8-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)dibenzothiophene (1), prepared from dibenzothiophene. The Suzuki coupling polycondensation of 1 with 2,7-dibromo-9,9-dioctylfluorene, 3,6-dibromo-9-octylcarbazole, or 1,4-dibromo-2,5-dioetyloxybenzene afforded the corresponding dibenzothiophene-based polymers. The measurements of photoluminescence indicated that all these polymers exhibited blue emission in solution. The copolymer containing dibenzothiophene and 9,9-dioctylfluorene units exhibited higher thermal stability than poly [(9,9-dioctylfluorene-2,7-diyl)], although the quantum yield of copolymer was lower than that of poly[(9,9-dioctylfluorene-2,7-diyl)]. (C) 2003 Wiley Periodicals,